Fast food causes 'infection' in mice

DW: As part of your research, you fed mice the equivalent of a Western diet rich in refined sugar, salt and saturated fats - so no fresh fruit or vegetables. What were you able to see?

Eicke Latz: What we see after the first few days [is that] the mice get a little sick - something they would get if they had an infection. So you can see that the blood cells start to grow in a certain direction, the bone marrow makes more monocytes and neutrophils - immune cells. And you see a lot of cytokines, these are mediators that immune cells make to alert other immune cells that there's something going on. So it looked like an infection.

So people who have inflammation in their bodies due to other illnesses - is this going to be exacerbated by the Western diet?

Yes. We know from medical studies that diets can have an impact on inflammation in other diseases - for example, rheumatoid arthritis patients. They know when they've had a "sinful" diet, if I may say so, because they do worse the following day or the following week.

So I probably should give up the packet of chips and the chocolate and the bottles of Coke.

Yes, you should.

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Would there be any change in our bodies if we stopped eating a diet rich in sugar, salt, saturated fats and replaced it with a healthy one? Would our bodies go back to the way they once were?

What we found is that dietary changes to regular diets - with the mice it's called the "chow diet," which is a grain-based diet - led to changes. But it took a long time for the immune system to calm down. In fact, even four weeks after a dietary change, we could still see activated immune cells sitting in the body and all kinds of places, waiting for potential other triggers, like infections.

Is there any indication that what I eat now - that my children or my grandchildren might suffer from that in future?

We're actually studying this. So [with mice], we froze the sperm of the fathers that had this Western-type diet, and also the fathers that first had a Western-type diet and then went back to a regular "chow diet." And we wanted to make new mice using the sperm and study their immune systems and see whether the grandfather or the father that had the wrong diet - whether this is transmitted. Because there are indications from other areas, for example with diabetes, that these types of what we call "epigenetic changes" can also be transmitted to the second or even the third generation.

Dr. Eicke Latz is the director of the Institute for Innate Immunity at the University of Bonn and a researcher at the the German Center for Neurodegenerative Diseases (DZNE).